Apparatus for making cellulose xanthogenate



.M 1932- J. H. BARTLETT 1,

APPARATUS FOR MAKING CELLULOSE XANTHOGENATE Filed July 9, 1929 4 Sheets-Sheet 1 March 1932- J. H. BARTLETT APPARATUS FOR MAKING CELLULOSE XANTHOGENATE 4 Sheets-Sheet 2 Filed July 9, 1929 March '8, 1932.' J. H. BARTLETT 1,848,095

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APPARATUS FOR MAKING CELLULOSE XANTHOGENATE Filed July 9, 1929 4 Sheets-Sheet 4 Patented Mar. 8, 1932 .UNITED STATES PATENT OFFICE.

JAMES H. BARTLETT, OF CHESTER, PENNSYLVANIA, ASSIGNOR OF ONE-THIRD TO I JOHN C. HLNKSON, OF CHESTER, PENNSYLVANIA APPARATUS FOR MAKING CELLULOSE XANTHOGENATE Application filed July 9, 1929. Serial No. 377,036.

In the manufacture of artificial silk or "rayon, the commonly practiced method of producing the cellulose involves the use of three primary machines, the first of which is known as the grinder, in which the alkaliaed cellulose is ground, and from this machlne the ground product is conveyed to the xanthating machine or tumbler, and then to the churn or mixer. In the machine known as the tumbler, the stock is mixed with carbon disulphide, which liberates a noxious gas, and it is necessary to remove this gas in order to protect the workmen. The transfer of the material from one machine to another is laborious and also time-consuming.

The present invention is designed to substitute for these three machines a single machine, which is hereinafter referred to as a converter, and in which the stock is ground, tumbled and churned successively, and made ready for the subsequent operations usually carried out in the manufacture of artificial silk or rayon.

The invention relates to the single machine referred to.

The invention consists of a specially designed and constructed machine, into which the raw material, cotton, cotton linters, waste, wood, corn stalks and any other suitable vegetable or mixed substance or material, is introduced and ground by means of my newly invented grinding agents, and then the ground material is exposed to the action of caustic soda and carbon disulphide in' the same machine, while being churned, after which the xanthated product is subjected to the usual treatment of filtering, ripening and then spinning. This describes the use of the.

invention when employing the alkali method of production, but the invention is alsosusceptible of use in connection with the cupraammonium process.

In the accompanying drawings illustrating the invention, in the several figures of which like. parts are similarly designated, Figure 1 is a front elevation with a small portion broken out near the bottom. Fig. 2 is a side elevation. Fig. 3 is a transverse vertical section taken on line 3-3 of Fig. 1. Fig. 4 is a perspective view of one of the cutters detached. Fig. 5 is a sectional elevation illustrating the mounting of the vessel.

The machine or so-called converter, comprises a vessel composed of an outside casing 1, which may be of steel, in a single piece or 55 in sections, and of suitable shape, preferably having a rounded bottom 2 and an angular top 3 made of steel or other suitable metal, and a lining 4, preferably of Monel metal, or other suitable non-corrosive metal. The vessel is supported at opposite sides by means of shafts 5 and 6, which, in turn, are supported on frames 7 and 8. These shafts are secured to the casing and the lining. Between the outside casing and the lining, a space is left to form a chamber 9 for containing a circulating cooling agent, which may be introduced through a suitable inlet 10 and discharged through a suitable outlet 11, and returned to the supply medium for reuse in 7 the space 9. h

The chamber 9 is provided with brine or other cooling agent admitted at the top, as through a hose connected with the inlet 10, and discharged through the bottom, as 7 through the outlet 11. This chamber extends throughout the sides and ends of the vessel and is closed at the top, as by any suitable header 12. The top 3 has a flange 13 resting upon the packing 14 interposed beso tween it and the member 12 and adjacent flange 15; bolts or other fastenings 16 being used to hold the top to the casing in a leaktight manner.

One end of the top is provided with a a; hinged door 17 opening upwardly and secured in a leak-tight manner by bolts and nuts or other fastenings 18. The raw material for use in the viscose process is introduced into the vessel through this door. This door is provided with a glazed peep-hole 19 for inspection of the interior of the vessel. This peephole may be provided with a suitable wiperfor keeping the glass clean. The

top of the part 3 is provided with an inlet 20 9 through which the stuff to be treated is introduced into the vessel in the case of the cupraammonium process, and this inlet is provided with a leak-tight hinged cover 21. The bottom is provided with an outlet 22 which also roller bearings or other anti-friction means 28,

packed in place and held therein by rings 29 projecting inwardly from caps 30 which are secured to the bearing blocks by bolts or screws 31. A secondary shaft 32 extends through the shafts 5 and 6 and has interposed between itself and the shafts 5 and 6 the roller or other anti-friction bearings 33 suitably packed at 33 within the shafts, and having endwise packing-adjusting rings 34 which are set up, as needed, by means of the pressure screws 35, mounted in the caps 30; The shaft 32 is also packed fromthe 1nsid e at 33, and this lastmentioned packing is adjustably held in place, as by a gland 33".

Thrust bearings may be provided at opposite sides of the vessel, one such being shown in detail, but conventionally, in Fig. 5, and comprising a thrust bearing houslng a provided with an extension I) which may be bolted or otherwise secured to the bearing parts 7 and 27, and within this housing 1s any suitable roller bearing 0 having the ballrace (1 bolted to the shaft 32. Any other suitable thrust bearing may be used in place of the one shown.

As will be obvious, it is necessary to have the joints leak-proof in order to prevent the escape of fluids and fumes contained in the vessel. One source of danger in the operation of this class of machinery is found in the chemicals used, and hence the precaution of packed and leak-proof bearings is essen-.

tial.

In the type of bearings shown in Fig. 5, the lower bearing blocks may be attached to or be apart of the frames 7, while the upper bearing blocks are adapted to be bolted down upon the lower bearing blocks; and the construction should be such that access may be had to thebearings. I

The vessel may be mounted in its frames in such manner as to be capable of being rocked or rotated, and to this end, one end of the vessel may be provided with a toothed wheel 36 engaged by driving pinion 37 which may be connected with any suitable source of power by means of a shaft 38.mounted in a bracket 39 which may project from one of the frames 7.

As will presently appear, there are times in the process forming part of this invention, when it is necessary that the vessel be held stationary, and for this purpose any suitable means may be used, such as props 4O engaging abutments 41 on the outside of the vessel and stops 42 on the floor, indicated by the line 43. These props may be readily removed and as readily applied as required in the operation of the machine- The shaft 32 has mounted on it a number of fast and loose pulleys 44, 45 and 46 by which various speeds may be given to the shaft. On this shaft and within the vessel are mounted a pair of oppositely curved holders 47 supported by the arms 48 and 49 fast on the shaft, the curvature of the holders being such that one of them reaches from the center of the vessel outwardly toward one side in one direction and the other similarly reaches from the center outwardly toward the other side in the other direction. These holders are provided with removable cutting blades or knives 50, shown in detail in Fig. 4, having teeth 51 extending in the direction opposite to the direction of rotation. ture of the holders, and they are provided with three, or more or less, bolt holes 52 at opposite ends, and intermediate bolt holes 53, to receive bolts by which said blades may be readily secured in position on their holders and easily removed when not needed. The blades are accessible by opening the door 17 in the top. These blades cooperate with the oppositely grooved plates 54 and 55, Fig. 1, arranged transversely in the vessel, which cooperation, when the blades are in rotation, serves to macerate or otherwise disintegrate and pulp the raw material from which the cellulose is made. There is sufiicient clearance between the cutting edges of the blades and the oppositely grooved plates 54 to prevent clogging and yet insure the necessary These blades conform to the curvagrinding or macerating action upon the raw' material; the projection of the teeth 51 contributing to the prevention of clogging while in nowise impeding the reduction of the raw material for further treatment.

The material having been introduced into the vessel, and the vessel propped by the props 40, so as to be held stationary, power is applied to the shaft 32 so as to rotate the blades 50 and cause the reduction of the raw material, and when it is sufiiciently reduced, the props 40 are removed so as to free the vessel for rotation uponthe bearings for its shafts 5 and 6. To effect such rotation, motion is imparted from shaft 38 through pinion 37 to the gear wheel 36, which last is fast to the vessel. The reagent, such as carbon disulphide, is admitted to the vessel through the shaft 32, which, for this purpose, may have one end hollowed out, as shown in Fig. 5, at 56, and provided with lateral holes 57 opening into the vessel. The reagent is contained in a remote container, not shown, which is connected with the outer end of shaft 32, by a pipe 58, Fig. 1, and suitable coupling 59 packed to prevent external escape of the reagent and its fumes and yet, permit rotation of the shaft 32. The pipe 58 is provided with a valve 60 for controlling the admission of the reagent from time to time as needed in carrying out the process. lhe rotating arms, blade holders, and blades, serve as impellers to agitate and thoroughly mix the mass under treatment.

The knives are removed, if at all, after the grinding is completed and before the admission of the reagent. When the grinding is completed, the knives may be removed, if desired, and then the reagent is admitted and the rotation of both the vessel itself and the impellers proceeds. the vessel turning at the rate of six R. P. M. and the impellers at the rate of seven R. P. BL, the rotation continuing until the mass shows the proper color, say, in about four hours. Then tlie vessel is blocked by replacing the props, and then the impellers are started at about the rate of ten R. P. M. and caustic soda solution is admitted into the vessel through the inlet 61 in sufficient quantity at once or preferably at intervals, about one half of the necessary quantity of the caustic soda solution being admitted within the first ten minutes. Then the rotation of the impellers is accelerated to about one hundred R. P. LL, adding, meanwhile, a quantity of the caustic soda solution 'to obtain the proper viscosity.

The thus processed mass is then ready to be withdrawn and may be withdrawn from the bottom opening 22 through a suitable discharge line and conveyed away for the necessary further treatment to prepare the material for spinning.

Thus it will be seen that the usual three operations of grinding, tumbling and churning are performed upon the'material in succession, and without removing the material from the converter and conveying it from a grinder to a tumbler or mixer and thence to a churn, thus saving time in producing the material and also reducing to a minimum the chance of escape of noxious fumes which are a constant source of annoyance and oftentimes danger to the operatives. The desired processing of the material avoids the necessity of the presence of the usual humidifying apparatus at a saving of about eighty per cent, and reduces the labor cost about sixty per cent.

In the use of the machine for carrying out the cupra-ammonium process, the vessel is propped up so as to remain stationary, while the impellers are rotated. The cupra-ammonium is introduced through the inlet 61 in the required quantity, and the cover 21 is opened and the material to be reduced is admitted slowly into the vessel and is agitated through and with the cupra-ammonium solution by the impellers, until the proper viscosit-y is obtained, say, for about one hour and a half. The material is then ready for the subsequent treatments to prepare it for spinning, and may be discharged from the vessel through the opening 22 at the bottom. The knives may or may not be used in this process, but all of the steps necessary to convert the material from the raw state into the finished solution are completed in this one machine and by means of a single continuous operation.

The inlets l0 and 61 are shown as globe valves, but it will be understood that any kind of inlets may be used to which hose or other supply pipes may be readily coupled and as readily uncoupled. L

In Figs. 1 and 2 pairs of fast and loose pulleys are shown for transmitting motion to the movable parts, but asindicated in Fig.-

5, these pulleys may be replaced by a. sprocket wheel 62 and chain drive to an individual motor for each machine.

Variations in the details are permissible within the principle of the invention and the claims following.

What I claim is 1. A machine adapted for use in succeively grinding, tumbling and churning cellulose xanthogenate preparatory to its treatment for spinning, same consisting of a vessel mounted to rotate and having a secondary transverse shaft, arms mounted within the said vessel in pairs at the center of said shaft and near the sides of the vessel and extending radially from said shaft, and holders mounted on each pair of arms and extending in curved lines from the central arms toward the side arms and provided with toothed blades, the teeth of the blades extending in a direction opposite to the direction of rotation.

2. A machine adapted for use in successively grinding, tumbling and churning cellulose xanthogenate preparatory to its treatment for spinning, same consisting of a vessel having a leak-tight top, trunmons on which the vessel is mounted, said vessel containing a suitable number of knivesreach- "ing from center to sides crosswise of the vessel, means to independently rotate the vessel on its trunnions, a secondary shaft mounted within the trunnions and on which shaft the knives are mounted, adjustable roller bearings interposed and packed between thev mountings for the vessel andsaid secondary shaft, means for introducing a chemical reagent into the vessel without opening the vessel, and means for discharging the contents.

3. 'A machine adapted for use in successive- 1y grinding, tumbling and churning cellulose xanthogenate preparatory to its treatment for spinning, same consisting of avessel having a leak-tight top, trunnions on which the vessel is mounted, means to rotate the said vessel, a secondary shaft mounted in the trunnions and passing through the vessel, one end of'said secondary shaft being hollowed out to provide an inlet for a chemical reagent, grinding knives of opposite curvature mounted on said secondary shaft within the vessel and extending in opposite directions from the center of said shaft toward the sides of said vessel, and leak-tight packed roller-bearings interposed between the trunnions and their mountings and also between the trunnions and the secondary shaft.

In testimony whereof I have hereunto set my hand this 2nd da of July A. D. 1929.

\ JA S H. BARTLETT. 

